1. Field of the Invention
The invention relates to an overhand sewing machine for the sewing of innersoles to the shank with two driven conveying disks applied, respectively, against the innersole and shank material.
2. Description of the Prior Art
Overhand sewing machines of this type are used in the production of turned shoes. In this process, specific difficulties are encountered while sewing along the heel curve of the innersole and the shank, because of the relatively small radius of the arc along which sewing must take place and because, due to the thickness of the inner sole and shank materials, the lengths of the rolling paths of the conveying disks may be different to the extent that the material to be sewn may become warped and/or wedged between the transport disks.
Overhand sewing machines are already known (DE-OS No. 18 04 370) wherein the two conveying disks may be driven with different step length, and it is also known to use such overhand sewing machines in the manufacture of turned shoes. However, it is difficult to set the mutual relationships of the lengths of the steps with the accuracy required for the sewing of an innersole to the shank of a shoe in order to obtain a satisfactory conveyance of The material to be sewn along the heel rounding of the innersole and the shank.